BibTex format
@article{Ng:1999,
author = {Ng, CS and Desai, SR and Rubens, MB},
journal = {Journal of thoracic …},
title = {Visual quantitation and observer variation of signs of small airways disease at inspiratory and expiratory CT},
url = {http://journals.lww.com/thoracicimaging/Abstract/1999/10000/Visual_Quantitation_and_Observer_Variation_of.8.aspx},
year = {1999}
}